JP4562860B2 - Electrohydraulic brake device control method and control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The invention relates to an electrohydraulic brake device according to the superordinate concept of claim 1 and to its control method and device according to the superordinate concept of claims 3 and 18.
[0002]
[Prior art]
From German Patent Publication No. 1965154, an electric motor driven pump capable of switching on and off is provided, the inertia running time of the pump after shut-off is determined, and for increasing or decreasing the braking force as a function of the inertia running time It is known how to control a brake device in which the control signal is corrected. By this method, the temperature of the brake device is evaluated. An electrohydraulic brake device that can supply hydraulic fluid from the accumulator to each wheel brake / cylinder via a valve means for control is not the subject of this document.
[0003]
From German Offenlegungsschrift 19604126, a method for controlling a vehicle brake device is known in which the pressure is increased and / or decreased by at least one control signal having at least one variable parameter. In this case, at least one parameter is corrected as a function of at least one variable that adjusts the pressure change dynamics. The adjustment variable includes in particular the temperature of the hydraulic system or the ambient temperature. This document also does not cover the control of an electrohydraulic brake device.
[0004]
It is known that the function of an electrohydraulic brake device is limited at very low temperatures that significantly reduce the viscosity of the brake fluid. In this case, the operation of the provided valve or the operation of the pump filling the accumulator of the electrohydraulic brake device is significantly reduced, so that the pressure balancing process is only performed very slowly. At very high temperatures, the service life of the electrical components used is limited at high temperatures, which likewise limits the function of the electrohydraulic brake device.
[0005]
It is clear that the above prior art does not give optimum results in relation to each of the special problems in electrohydraulic braking devices.
[0006]
[Problems to be solved by the invention]
Accordingly, it is an object of the present invention to provide an electrohydraulic brake device whose functionality is improved not only at a high temperature but also at a low temperature, and a control method and apparatus for the electrohydraulic brake device related thereto.
[0007]
[Means for Solving the Problems]
This object is solved by an electrohydraulic brake device having the features of claim 1 and its control method and device having the features of claims 3 and 18.
[0008]
By measuring the temperature according to the present invention in an electrohydraulic brake device, a number of functional processes and monitoring processes that could not be considered in a normal electrohydraulic brake device can be performed. In particular at low and high temperatures, it is possible to guarantee a problem-free functionality or improved functionality of the electrohydraulic brake device.
[0009]
Advantageous embodiments of the electrohydraulic brake device according to the invention and its control method and device according to the invention are set forth in the following description and are the subject of the dependent claims.
[0010]
Suitably, the temperature measuring means comprises at least one temperature sensor. It is particularly preferable to use a plurality of temperature sensors so that two to three choices can be made from a safety point of view in order to allow operation and monitoring of the device relating to temperature even in the event of a failure of the temperature sensor. Clearly it is advantageous. For example, a temperature measuring element provided in the pressure sensor can be used as the temperature sensor. However, similarly, a temperature sensor device may be provided in addition thereto.
[0011]
A particularly preferred embodiment of the method according to the invention minimizes the heat generation process taking into account the sufficient functionality of the electrohydraulic brake device as a function of the measured temperature. For example, in the case of continuous brake operation, current must flow for a long time to the switching valve and the shutoff valve of the electrohydraulic brake device. The heat generated in the valve with the components in the control device steadily raises the temperature of all components. At this time, the temperature signal measured according to the present invention can identify that the temperature has exceeded the set limit value. Based on this information, any heat release process in the control device from the control device can It can be changed or minimized in view of its partial heat quantity, in which case functional constraints can be taken into account while constantly maintaining the necessary basic braking function as the temperature rises.
[0012]
For example, if a limit value is exceeded, in addition to the execution of various means, these means may be at least partly visually indicated to the occupant, in particular the driver. This means, for example, that a particular heat generation process is interrupted or that the functionality of such a process is reduced, which is indicated to the driver, for example by an indicating device on the instrument panel or by other visual indicating devices.
[0013]
To prevent overheating of the electrical and mechanical parts required for control (for example in a built-in control device, ie a control device directly incorporated in a hydraulic device) when a preset temperature limit is exceeded in the control device For example, the following method or attachment means may be selected. That is, the front axle is first switched to backup operation (settable reset level), so that the valve on the front axle is not operated, and pressure control is performed by opening the balance valve on the rear axle. Good. If the temperature further increases, the electrohydraulic brake device may be further returned to full backup reset level until it reaches a correspondingly lower temperature partially or completely again. Thus, engagement to the reset level determines at least one function level of the electrohydraulic brake device, for example to reach this function level by deriving a specific means to interrupt a predetermined function. Can do. If there are multiple reset levels, the lowest reset level used in closed-loop or open-loop control of an electrohydraulic device is the minimum level that guarantees a functional minimum or basic function for the control used. is there. As closed-loop or open-loop control, any open-loop or closed-loop control that adjusts the braking and / or running stability and / or safety of the vehicle can be used for the electrohydraulic brake device. Here, the full backup reset level indicates a case where the closed loop or open loop control is interrupted and only the remaining hydraulic / mechanical engagement is used.
[0014]
It is suitable for the purpose to change the pulse / pulse pause ratio as a function of the measured temperature in the cyclic repetitive operation (cyclic operation) of the pump in the electrohydraulic brake device. Usually, the pump of an electrohydraulic brake device is fully operated when the pressure in the accumulator drops below the minimum brake value. Above this threshold, the pump is typically operated cyclically (cyclically) in order to keep the noise level as low as possible. The only exception to this closed loop or open loop control scheme is usually the situation where a very large drop in accumulator pressure can be inferred based on the pressure course of the accumulator. However, if the temperature is very low, the pump's supply capacity will be reduced, which will cause the number of additional cycles to further increase the pressure build-up time of the accumulator and thus reduce the availability of the device. Such a slow pressure rise, for example, in the absence of other information, will cause the pressure rise to be initially invalid and infer that there is an error in the device. I will let you. The temperature information made available by the present invention can be used to determine that this low temperature characteristic of the charge pump is reasonable, thereby avoiding erroneous shut-off of the electrohydraulic brake device. Thereby, even when the low temperature time is short (for example, until the engine room is heated), it is possible to maintain the usability of the electrohydraulic brake device, that is, this state of the electrohydraulic brake device is temporarily changed. It can be distinguished from a low temperature state.
[0015]
In the control of the device pressure in an electrohydraulic brake device, it is clear that it is advantageous to take into account the measured temperature, in particular during the pressure increase in at least one wheel brake by opening the corresponding inlet valve. For example, the pressure control device of an electrohydraulic brake device that controls the pressure set in the wheel brake as a function of the driver's wish or anti-lock control device control signal and / or drive slip control control signal vibrates at low temperatures. Tend to. This further affects the control of the vehicle braking and / or driving stability and / or safety. This effect is based on the physical change characteristics of the brake fluid at low temperatures. For example, a pressure wave is formed when the inlet valve is opened due to a pressure rise in the wheel brake, and this pressure wave is based on a change in the elasticity of the brake fluid at low temperatures, and is essentially time changed compared to high temperatures. Will give the characteristics. For pressure control, this generally means the phase lag between the actual pressure value and the measured wheel pressure value (within the hydraulic system). By measuring the device temperature and taking it into account, in control, such as when the temperature is low, such a phase delay can be taken into account in the control process when a low temperature is detected.
[0016]
It is clear that it is advantageous to use the measured temperature for the evaluation of the pressure in the accumulator. In an electrohydraulic brake device that is operating normally, the pressure acting in the accumulator is continuously read, so that the pump can be operated until the desired accumulator pressure is reached. . For this purpose, an accumulator pressure sensor is usually used. When this accumulator pressure sensor fails or when the sensor connection line forms a short circuit with an adjacent pin or connection terminal, the pressure difference of the hydraulic pressure at the wheel inlet valve is estimated from the control current to the control valve. Therefore, the accumulator pressure can be estimated when the wheel side pressure is known. In addition, other methods are known that allow evaluation of the accumulator pressure.
[0017]
Until the first pressure rise is detected by the wheel pressure sensor, the inlet valve control valve of the rear axle is operated by the lapse of current / time having a gradient, and when this is detected, the pressure is immediately lowered again. It is advantageous that a pressure increase is detected without any disturbance. The wheel is disconnected from the electrohydraulic brake device or switched to a pressure-free state so that no superposition of disturbances due to non-linearities in the valve current / open pressure characteristic curve occurs during partial braking. The amount of current indicating the pressure rise is a measure for the pressure difference of the hydraulic pressure in the valve. Thus, in general, when the pressure accumulator pressure information does not appear due to an error or when the pressure accumulator pressure sensor fails, it is possible to evaluate the pressure accumulator pressure with sufficient accuracy in order to ensure emergency operation. Due to the presence of temperature information on the electrohydraulic brake device according to the present invention, the conversion of the control current into electromagnetic force, and hence the calculation of the pressure difference at the inlet control valve, can be performed accurately, and therefore accurate and reliable pressure accumulation. The vessel pressure can be evaluated. Furthermore, when there is a low temperature, the current gradient can be made gentle by taking into account the changed time characteristics of the low temperature brake fluid. In summary, by taking into account the temperature of the electrohydraulic brake device, the reliability of emergency operation is improved.
[0018]
Furthermore, it is advantageous that the measured temperature is generally used in the control of the pressure regulating device of each wheel brake.
Suitably the measured temperature is used for charging and / or discharging monitoring of the accumulator. During pump operation, it is monitored whether the pressure gradient in the accumulator is a reasonable value. Since the low pressure gradient that can be generated by the pump at a low temperature of, for example, about −30 ° C. must also be covered, the acceptable validity band must usually be taken relatively wide. By using temperature information, this validity band can be significantly narrowed, thus allowing effective monitoring of accumulator filling. Especially when starting or starting at low temperatures, the pump supply may be so small that the accumulator is not filled. In this case, it is possible to start in consideration of a temporary backup device. At this time, the electrohydraulic brake device can be turned on immediately when the corresponding temperature signal is obtained. Thus, the temporary backup device can control the functionality of a particular reset level, in particular the functionality of a reset level having basic functions. Similarly, however, multiple functional reset levels can be managed and used by a temporary backup device.
[0019]
It is clear that it is advantageous to take the measured temperature into account when monitoring or inspecting the valve before, during and / or after the vehicle has traveled. For example, pressure balancing processes, such as those performed for so-called pre-drive checks or drive checks for monitoring switching valves and control valves (valve checks for certain functions), can take a relatively long time at low temperatures. I need. Due to the consideration of temperature information according to the present invention, the latency / filtering time for such effects can be adapted as a function of temperature (eg extended at low temperature and shortened at high temperature), thereby preventing false interruptions. Secure protection is guaranteed.
[0020]
Similarly, it is suitable for the purpose that the measured temperature is taken into account in the monitoring by the pedal stroke simulator (PWS). Monitoring with a pedal-stroke simulator examines the relationship between measurements that indicate the driver's wishes. In order to reliably detect the driver's wishes, it is important to measure various physical quantities such as, for example, pedal stroke and pedal force or pressure derived therefrom, such as plunger piston stroke or master brake cylinder pressure. is there. These values can be monitored as the upper and lower limits can generally be determined, at which measured values must be within the range. If the measured value is outside these tolerances, an error is detected and a corresponding emergency operation is entered. The hysteresis effect due to frictional force as a function of temperature significantly expands this range occurring in electrohydraulic brakes that operate according to design. Especially at low temperatures, large deviations occur essentially due to the relationship applied at high temperatures. In order to increase the inspection accuracy, it is advantageous for the tolerance range to be increased or decreased as a function of the temperature of the brake device.
[0021]
Suitably the measured temperature is used for monitoring the discharge level at the reset level. For this purpose, a small amount of liquid or hydraulic fluid is supplied into the wheel caliper by means of precisely defined pulses (eg opening the inlet valve for a predetermined time), followed by how much static pressure is set. Can be identified. Since this pressure is significantly affected by the existing temperature, the pressure / volume characteristic curve is a function of temperature, so that such a measurement can be accurately performed by considering the temperature.
[0022]
Furthermore, it is clear that it is advantageous to take into account the measured temperature in the monitoring of the pressure accumulator consumption. The formed pressure accumulator is designed as a consumable part or a replacement part. Therefore, the functionality of this accumulator must be periodically checked. Gas fill pressure may be used as a measure for accumulator accuracy. However, this gas filling pressure is significantly temperature-sensitive (for example, 60 to 120 bar over the temperature range of −40 ° C. to 120 ° C.). Here, when considering the device temperature, an inherently more accurate measurement can be performed, thus indicating whether the accumulator must be replaced.
[0023]
Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings.
[0024]
DETAILED DESCRIPTION OF THE INVENTION
The electrohydraulic brake device of FIG. 1 includes a master brake cylinder HBZ provided with a storage container 10, and a brake pedal that can be operated by a driver is mounted on the master brake cylinder HBZ. In addition, a hydraulic device 14 is provided, which includes a valve device and a pump device for controlling the wheel brakes 16, 18, 20 and 22. Coupled with the brake pedal 12 is a brake pedal switch 24 that closes when the brake pedal is operated and a measuring device 26 for measuring the stroke of the brake pedal. The brake pedal switch 24 may be formed as a simple normal open contact, or may be formed as a double switch having a normal close contact and a normal open contact in order to improve monitoring. A special embodiment shows the brake pedal switch 24 as a stop lamp switch BLS. Similarly, the measuring device 26 for measuring the stroke S of the pedal 12 may be provided in an overlapping manner. Further, a pedal stroke simulator PWS is provided, and the pedal stroke simulator PWS simulates a reaction force acting on the driver when the brake pedal 12 is operated. Two brake circuits HZ1 and HZ2 are connected to the master brake cylinder HBZ. Shut-off valves MV_TVR and MV_TVL are inserted into the brake circuits HZ1 and HZ2, respectively, and these shut-off valves are closed when current flows in the electrically operated brake device. A pressure sensor 28 measures the pressure applied by the driver via brake pedal operation in at least one brake circuit before the shut-off valve. When the shut-off valve is closed, the master brake cylinder is hydraulically shut off from the pressure control device. The pressure control device includes a pressure adjusting device for brake pressure control for each wheel brake and cylinder. In this case, each pressure regulator measures one inlet valve (MV_UVR, MV_UVL, MV_UHR, MV_UHL), one outlet valve (MV_DVR, MV_DVL, MV_DHR, MV_DHL) and one in the piping leading to the wheel brake, respectively. It consists of two pressure sensors 30, 32, 34 and 36. Within both front wheel pressure regulators, there is one media isolation piston 38 and 40, respectively, between the valves (inlet and outlet valves) and the pressure sensor or vehicle brake. The pressure regulators are coupled via pressure balance valves MV_BVA and MV_BHA, which can be controlled independently of each other by passing current. In addition, pressure release valves MB_EVA to MV_EHA are provided for each axle, and these pressure release valves enable the pressure drop from the wheel pressure regulator of the axle in the absence of current flow. These pressure relief valves couple the axle pressure regulator with a return line leading to the storage vessel 10. In the electrically controlled operating state, both valves are constantly energized, i.e. both valves are closed. Further, temperature compensation valves MV_TKVL and MV_TKVR are provided for the respective front wheel pressure adjusting devices. These valves are closed when no current is flowing, and are opened by passing current to reduce the pressure from the front wheel pressure regulator when there is a predetermined condition, especially when there is very long braking. The temperature compensation valve connects the brake pipe leading to the wheel brake to the return pipe. The energy for adjusting the brake pressure is supplied from a motor driven pump 42, in particular a single piston high pressure pump. This pump 42 is connected to a pressure accumulator 44, in particular a high pressure accumulator, which acts as an intermediate buffer and the pressure in the pressure accumulator 44 is measured by a pressure sensor 46. The pressure piping of the pump 42 leads to the wheel brake inlet valve, while the suction piping of the pump 42 is coupled to the storage container 10. Reference is made to the preferred embodiment shown in FIG. 1 for details of the hydraulic circuit. In one embodiment, the pressure release valves MV_EVA and MV_EHA and the temperature compensation valves MV_TKVL and MV_TKVR are not provided. Here, based on the above safety considerations, six temperature sensors 100-105 are shown. These temperature sensors may be provided on the one hand as temperature measuring elements contained in the pressure sensors 30, 32, 34, 36 and 46 or on the other hand as separate temperature sensors. Here, the number of temperature sensors is determined based on reliability consideration that the correct two of the three are selected. Similarly, one pressure sensor may be used for each brake circuit, for example. In this case, basically a temperature evaluation is also performed. The control unit 200 performs an open loop or closed loop control process on the electrohydraulic brake device. Only four supply lines or output lines 201 are shown schematically for ease of illustration.
[0025]
In normal operation, the brake device shown in FIG. 1 operates as follows. Suppose the driver steps on the brake pedal. In this case, the driver receives a reaction force as a function of the stroke. The functional relationship between the reaction force and the stroke is formed by a predetermined characteristic of the pedal stroke simulator PWS. When a brake request is sensed via the pedal stroke simulator 26, the stop lamp switch 24 and / or the pressure sensor 28, the shutoff valves (MV_TVR and MV_TVL) and the pressure release valves (MV_EVA and MV_EHA) are closed. The pressure rises in the master brake cylinder HBZ, and the pressure is formed from the pedal force. From the signals of the stop lamp switch 24, the stroke sensor 26 and / or the pressure sensor 28, the driver's brake desire is calculated, for example, as a target deceleration or target brake force. From this brake desire, individual target wheel brake pressures are formed. These pressures are adjusted according to the running conditions and the slip conditions, respectively, and are controlled via a wheel pressure regulator by passing a current through the valve. The actual pressure at the wheel pressure sensor at each wheel brake in the closed control circuit is used to control the actual value to the target value. If the target pressures on the left and right wheels of an axle are different, the pressure balance valves (MV_BVA and MV_BHA) are closed and the inlet valve and the actual brake pressure in each wheel brake are controlled to the target brake pressure. The actual pressure is controlled to a predetermined target pressure by operating the outlet valve. In order to increase the wheel brake pressure, current is passed through the inlet valve until the desired target pressure of the wheel brake is formed by the desired dynamic characteristics. Similarly, the pressure drop is achieved by passing a current through the outlet valve, in which case the brake fluid returns to the storage vessel via the return line. The pressure relief valve is activated if the device is in error. When the electrical device fails during braking, all valves return to a state where no current flows. At this time, the pressure release valve opens the pressure regulator in the direction of the return pipe, so that the brake pressure is not shut off. Similarly, this valve balances the volume with the container in the temperature fluctuation in the neutral state. Therefore, this reset to no valve current if the electrical device fails during braking and the functionality of the pressure relief valve used for it corresponds to the above full backup reset level. At this full backup reset level, the hydromechanical basic functions are still executed.
[0026]
The pump 42 is activated when the pressure in the pressure accumulator 44 drops below a predetermined value. In addition to this function, the accumulator pressure measured by the pressure sensor 46 essentially indicates the pressure present at the inlet of the inlet valve, so that the accumulator pressure measured by the pressure sensor 46 is also evaluated within the control. The
[0027]
The above open loop or closed loop control process can be executed by the control unit 200. In order to make the figure easier to see, the connection line connecting the control unit with the individual components to be controlled of the electrically operated brake device is shown only on the control unit side and is generally indicated by the reference numeral 201. Reference numerals 100 to 105 denote temperature sensors, which measure the temperature of the hydraulic fluid or brake fluid and transmit it to the control unit 200 as described above. At this time, a control process or a monitoring process can be executed in the control unit as described at the beginning. Similarly, it is conceivable to transmit the temperature signal to other control units that are in operative coupling with the control unit 200.
[0028]
In the illustrated embodiment, six temperature sensors are shown. With this number of sensors, good reliability considerations are possible (eg two out of three per brake circuit, ie the sensor signal is considered correct when two sensors match in three sensors) As such, the electrohydraulic brake device can be further operated and managed by the present invention even if one sensor fails. The line length to the temperature sensor is selected based on the illustration and thus does not indicate a functional relationship. In addition to the temperature sensors shown here that can directly measure the hydraulic fluid temperature or brake fluid temperature, there are also sensors that measure or determine the temperature of electrohydraulic brake devices or hydraulic devices based on the temperature of components such as valves. It can also be used.
[0029]
FIG. 2 shows in a flow diagram how the temperature information is evaluated. In block 300, temperature measurement or temperature evaluation is performed. Similarly, a start condition and a stop condition for the method are identified at block 300. The start condition may be, for example, an operation of a start switch of the vehicle, and thus may be a start signal. At this time, a new operation for blocking will correspond to a possible stop condition. On the other hand, the course of the method may be kept for a certain time after shut-off, for example to perform a later valve check or other device check. A query 301 is reached with the temperature T measured from block 300. Here, in the inquiry 301, it is inquired whether the temperature T is lower than the first limit value TG1. If the inquiry is affirmative, block 302 is reached, in which means M1 assigned to this first temperature limit value TG1 is executed. When the temperature T reaches or exceeds TG1, the inquiry 303 is reached. Here, in the inquiry 303, it is checked whether or not the temperature T is lower than the second limit value TG2. If this inquiry is affirmative, in block 304, the second means M2 having a correlation with the temperature limit value TG2 is started. Here, when the second limit value TG2 is reached or exceeded, the next inquiry is reached. This may be performed using a number of arbitrary limit values TGn. In this way, the final inquiry 305 is reached, and it is checked in the final inquiry 305 whether the temperature value T is below a limit value TGn, for example. If this check is affirmative, the means Mn related to the limit value TGn are started or executed in block 306 as well. Block 307 is reached when the highest limit value, eg TGn, is reached or exceeded, and in block 307, means Mn + 1 for temperature values much higher than TGn are performed. Therefore, in the above example, that is, the conditions shown in the inquiries 301, 303, and 305, start from the positive limit value TG. However, this method can also be implemented for temperature values TG less than 0 ° C. or composite limit values less than 0 ° C. and greater than 0 ° C. In this case, it is generally important that the attached specific means M is implemented in the electrohydraulic brake device for a specific temperature or temperature range.
[0030]
Thus, means M also includes the above possible reset levels for specific functional relationships. Thus, in certain embodiments, different reset levels may be assigned to different settable or determinable temperatures or temperature ranges to minimize the heat generation process. At this time, for example, when the maximum limit value TGn is reached or exceeded, a full backup reset level will be assigned to the limit value TGn.
[0031]
From each means, block 300 is then reached again, at which temperature T is again measured. Thus, a specific time portion may be provided within the means block 302, 304, 306, 307 and the means are executed within this time portion before a new temperature T is measured. On the other hand, after passing through the respective block, it is possible to further execute or stop the means M, which are newly measured and derived as a function of the temperature T.
[0032]
In this case, the means M are used or changed for the control of the electrohydraulic brake device. Means M particularly indicate the field of use for open-loop or closed-loop control of electrohydraulic brake devices as described above and in the claims.
[0033]
A special embodiment for this is the use of temperature in terms of pump rotational speed.
The filling factor of the pump element or pump 42 is a function of the viscosity of the brake fluid. The viscosity of the brake fluid varies significantly with temperature. When the pump 42 is driven at a rotational speed nopt at which the filling degree of the pump is optimally large, this rotational speed increases the supply flow rate of the pump. This supply flow rate is greater than when the pump motor is at full rotation speed and at low temperatures and the pump is almost not filled. Thus, if the pump motor rotational speed is adapted via temperature so that the degree of filling of the pump is optimal, this increases the pump supply flow rate. Accordingly, the pump motor is operated periodically (cyclically), and at this time, the pulse / pulse pause ratio is adjusted, so that the rotational speed n of the pump is always set to the optimum degree of filling of the pump. Set to Therefore, since there is a significant functional relationship between the viscosity and the temperature T, the pump rotational speed n is also a function of temperature. For FIG. 2, this means, for example, that various pump rotational speeds n can be set as a function of the respective temperature limit TG. Therefore, the pump is operated at the rotational speed n1 until the temperature limit TG1. In the second temperature interval up to TG2, the pump rotation speed is changed to n2. Here, this continues to the limit TGn, and until this limit TGn, the pump is operated at a certain rotational speed nn. Of course, the rotational speed nn + 1 is used above the temperature limit TGn. Therefore, in some cases, the pump rotational speed n may be increased linearly with the temperature T. The wide relative relationship actually observed between the pump rotational speed n and the temperature T basically increases the pump rotational speed in the same manner as the temperature increases, but the corresponding curve has a smaller gradient as the temperature increases. It shows that it becomes. Therefore, this curve does not change linearly, but changes with other functional relationships as shown in FIG. 3, for example.
[0034]
In this case, the curve shown by the broken line has a higher rotational speed than the curve shown by the solid line, thereby indicating a higher supply flow rate. Therefore, in FIG. 2, instead of using individual temperature ranges, that is, temperature limit values TG, the relationship may be formed by such characteristic curves or characteristic curve groups.
[Brief description of the drawings]
FIG. 1 is a hydraulic circuit diagram of a preferred embodiment of an electrohydraulic brake device.
FIG. 2 is a flow diagram illustrating a method of switching between various control means performed using various temperature limit values.
FIG. 3 is a diagram illustrating the relationship between pump rotational speed and temperature for a particular use or pump operation.
[Explanation of symbols]
10 Storage container
12 Brake pedal
14 Hydraulic system
16, 18, 20, 22 Wheel brake
24 Brake pedal switch
26 Measuring device (brake / pedal / stroke)
28, 30, 32, 34, 36, 46 Pressure sensor
38, 40 Medium isolation piston
42 Single piston high pressure pump
44 pressure accumulator
100, 101, 102, 103, 104, 105 Temperature sensor
200 Control unit
201 lines
BLS stop lamp switch
HBZ Master brake cylinder
HZ1, HZ2 Brake circuit
M, M1 ... Mn + 1 means
MV_BVA, MV_BHA Pressure balance valve
MV_DVR, MV_DVL, MV_DHR, MV_DHL Outlet valve
MV_EVA, MV_EHA Pressure release valve
MV_TKVL, MV_TKVR Temperature compensation valve
MV_TVR, MV_TVL shut-off valve
MV_UVR, MV_UVL, MV_UHR, MV_UHL Inlet valve
n, n1 ... nn + 1 Pump rotation speed
nopt Optimal rotation speed
PWS pedal stroke simulator
S Pedal stroke
T temperature
TG, TG1 ... TGn Temperature limit value
VA front axle
VR Front right wheel
VL front left wheel
HA Rear axle
HR Rear right wheel
HL Rear left wheel

Claims (15)

Can be supplied to the respective wheel brake cylinders via valve means a hydraulic fluid from the accumulator to the brake, also, the control method of the electric hydraulic brake unit can supply oil pressure liquid to the accumulator by the pump In
The electrohydraulic brake device includes:
At least one hydraulic fluid temperature measuring means for measuring the temperature of the oil liquid in electrohydraulic brake system,
In the open-loop or closed-loop control of the electrohydraulic brake device, the measurement temperature consideration means for considering the measurement temperature ,
The pump for controlling the wheel brake ,
The hydraulic fluid temperature is measured by the hydraulic fluid temperature measuring means ,
The electrohydraulic brake device is controlled in consideration of the measured temperature by the measured temperature consideration means ,
The measured temperature is compared with a temperature limit value of the Jo Tokoro,
Based on this comparison, the pump rotational speed is increased with the increase of the measurement temperature, as the gradient of the higher pump rotational speed measurement temperature increases becomes smaller, you characterized in that different rotational speeds of the pump is set conductive A control method for a pneumatic hydraulic brake device. The control method according to claim 1,
A control method , wherein at least one hydraulic fluid temperature measuring means for measuring temperature has at least one temperature sensor. The control method according to claim 1,
A control method, characterized in that the heat generation process is minimized in consideration of sufficient functionality of the electrohydraulic brake device as a function of the measured temperature. The control method according to claim 1,
Electricity to minimize heat generation processes within the hydraulic brake system, the control method characterized by various means are executed. The control method according to any one of claims 1 and 3,
A control method, characterized in that the pulse / pulse pause ratio is changed as a function of the measured temperature in the cyclic repetitive operation of the pump of the electrohydraulic brake device. The control method according to any one of claims 1 to 5,
In the control of the system pressure in the electro-hydraulic brake system, in particular during the pressure increase in at least one wheel brake by opening the corresponding inlet valve, the control method of measuring temperature characterized in that it is taken into account. The control method according to any one of claims 1 to 6,
A control method, characterized in that the measured temperature is used for the evaluation of the pressure in the accumulator of the electrohydraulic brake device. The control method according to any one of claims 1 to 7,
Control method, characterized in that the measured temperature is used for monitoring the filling and / or discharging of the accumulator. The control method according to any one of claims 1 to 8,
A control method characterized in that a measured temperature is taken into account in monitoring or inspection of a valve before or during driving and / or after driving. The control method according to any one of claims 1 to 9,
In Bae monitoring Dar stroke simulator control method characterized by measuring the temperature are taken into account. The control method according to any one of claims 1 to 10,
A control method characterized in that a measured temperature is used in the control and / or monitoring of the pressure regulating device of each wheel brake. The control method according to any one of claims 1 to 11,
Control method, characterized in that the measured temperature is used for monitoring the discharge state when at least one valve means has returned to its current-free state. The control method according to any one of claims 1 to 12,
A control method characterized in that the measured temperature is used to monitor the depletion state of the pressure accumulator. The control method according to any one of claims 1 to 13,
A control method, characterized in that the measured temperature is used for setting each desired functional reset level of the electrohydraulic brake device. A control device for an electrohydraulic brake device,
A first means by which the temperature in the electrohydraulic brake device is measured is included,
There is a second means for processing a value representing this measured temperature,
As a function of the value representing the processed temperature, claims 1 to 14 at least one control method electro-hydraulic brake system, wherein the third means for operating the electro-hydraulic brake system is provided by the Control device.

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